Method of making short pins



Jan- 8, 1952 A. F. zl'rzEwl'rz 2,582,063

METHOD OF MAKING SHORT PINS Filed April 1949 l n 7 Smets-sheet 1 Jan. 8, 1952 A. F; zVrzEwl-rz METHOD -UF' MAKING SHORT -P INS 7, sheets-sheet 2 @d Filed nApril 6, 1949 Jan. 8, 1952 A. F. znzEwl-rz 2,582,063

METHOD oF MAKING SHORT PINS v Filed April e, 1949 r7`smug-'shew s Filed April 6, 1949 7 Sheets-Sheer, 4

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Hwa/@0^ 'h Jan. 8, 1952 A. F. zl-'rz/Ewlz 2,582,063

METHOD OF MAKING SHORT PINS Filed 'April 6, 1949 7 SheetswSheet 5 .-Ezg- 31 a I /y/A.

Patented Jan. 8, 1952 METHOD OF MAKING SHORT PINS I Arthur Frank Zitzewitz, Chicago, Ill., assignor, by

mesne assignments, to Elastic StopNut Corporation `of America, Union, N. J., a corporation v of New Jersey Application April 6, 1949, Serial No. 85,7792

Claims. 1 g This invention relates to improvements in methods for making short tubular metal pins, and particularly spring dowel pins although it relates to the making of other tubular pins as well. v

Copending applications, Serial Nos. 41,633 and 184,082, filed by Howard Peters and Edward J. Haedike on July 30, 1948, and September 9, 1950, respectively, relate to a method and apparatus for making spring metal dowel pins. My present invention is in some respects similar to the method and apparatus of the foregoing application insofar as shearing, feeding and forming apparatus used therein is concerned, but is` an improvement thereon, in that by the methodand apparatus of my present invention it is possible to produce on the same rolling and forming machine disclosed in the foregoing application, much shorter pins than could heretofore be produced by rolling operations. By the method and apparatus of my present invention, I am able `to rapidly and economically produce short metal tubular spring pins by a series of continuous operations, which pins are muchfshorter than the-distances between guides entering and leaving the nips of adjacent rolls, in large quantities in a relatively short period of time, thus enabling the pins to be sold at a low price, and making their use feasible for various fastening operations, and for use wherever rollers or pins may` beused. The-principal object of my invention is1to provide a novel and improved process by whichshort metal tubular pins may readily and economically be produced in a continuous operation in a more facilemanner than formerly.' l

A more specific object of my invention 4vis to provide a new and improved method of forming short metal pins from continuous strip stock by av seriesiof rolling forming operationswherein a series of pins are formed from asingle blank during `the, initial forming operations, and. will separate into individual pins as soon as they are sufliciently formed to vbe self-sustaining throughout the remainder of the forming operations, and will, be finished in the form of individual pins of the desired length at the completion of the forming Operations 1 yA more specic object of lmy invention is to provide a novel and efficient method for forming short metal tubular pins from strip stock by groovinggthe stock into divisions equal` to the desired lengths of the finished pins withoutsevering the stock to form groove separated interconnected segments, then shearing the stock transversely tothe grooves into slugs orblanks of V U-shapes and C-shapes by a series of rollingoperations while guidingthe shapes as they are formed, and then forming tubular shapes therefrom while breaking the slugs into the individual segments along the grooves formed solely by the forming action thereon, prior to the final forming.

stages, but after the initial forming stages.

` A more specific object .of my invention is to provide a new` and improved method of forming short metal tubular spring pins having opposite beveled edges by first grooving the stockin the direction of the grain thereof with V-shaped grooves and at thesame time scarring the edgesv thereof, then shearing. the stock transversely lof the grain thereof in lengths equal to the required circumference of the finished pins and then feeding and rolling the grooved slugs through a series of rolling operations, the grooving of the slugs being of suicient depth to hold them in connected relation during the initial forming operations, and to permit them to break when selfsustaining through the nalforming operations, solelyby the rolling action thereon.

These and other objects of my invention will appear from time to time asthe following specification proceeds and with reference to the accompanying drawings wherein;v

Figure 1 is a plan view of an apparatus `for carrying out the process of my invention;

Figure 2 is a View of side elevation of the apparatus shown in Figure l, with the grooving apparatus broken away;

Figure 3 is a sectional View taken substantially along line III-III- of Figure 1;

Figure 4 is a fragmentary longitudinal sectional view taken through the grooving apparatus; y y

Figure 5 is a fragmentary transverse sectional view of the grooving apparatus, taken substanvlor adjustment. Y

As shown in Figure two scarring wheels are provided'to groove and divide the strip l I into extends across the side plates' |5I 5,fatthe entering zend 'of -the machin'ew Said angle support is shown' having a guide gr-oovev 6I extending transversely Vof the'machinealong the upper surrace of' its horizontal leg, whichis adapted to be engaged by a gib 63 depending from the plate 59 and extending transversely thereof. The gibbedguide along the plate 59 is formed by two spaced `guide members 64--64 secured to the upper surface of said plate as by machine screws 65-65. Said guide members extend along said1 plate and have lower facing recessed shouldered portions 66-66 adapted to engage the edges and upper side of the strip and guide it to the nip between the scarring wheels 5l'-5| and backing roller A56. The guide plate 59 and guide members 64-64 are. of a converging arcuate formation at their-inner ends so as to conform to the form of the scarring wheels 5I-f-5l and the backing roll 56 and to extend'well into the nip therebetween. 'A gibbed guide 61 is provided at the discharge end of the scarng'wheel 5l-5|. Said gibbed guide extends well into the nip between the backing roll 56 and saidfscariingwheels 5I-5l and like the guide 51 includes a plate 69 having shouldered guide members -10 extending therealong 'and secured thereto as by machine screws 1I. The plates, 59 and 69 are connected together by a connecting member 13 herein shown as being of a substantially inverted U-shaped formation. Said connecting member is connected at the ends of its legs tosaid plates 59 and 69 and extends along each side of and beneath the backing roll 56. A cross bar.14 secured at ends to the side platesl I5-,I5 serves asa. slidable support for said connecting membeij'and said gibbed guides 51 and 61. Said gibbed guides are likewise guided against lateral displacement by means of parallel spaced guide members 11 5-15 `connected between the side plates' vI 5-I 5 and slidably engaging the front an rear sides of the connecting member 13. v

The apertured portions of the guide strips v(i4- 64 and10-19 through which machine screws 6 5-,65 and 1I--11I extend may be slotted (not shown) to permit adjustment of said guide strips to accommodate the guide means to various' desired widths of strip.

The guides 51 and 61 are adjusted laterally with respect to the scarring wheels 5I5| in an obvious manner by means of two adjusting screws 16-16 adapted to engage the outer sides of the guide members 64-64 and threaded inupright lugs 11--11 projecting upwardly from the outer ends of the angle support 60.

.The backing `rol15i is journaled in bearing boxes 19-19 mounted in vertical guides 55-55 in the side plates I5---|5.A Each of said bearing boxes has a lug 89 projecting upwardly from its top surface and forming a seat for acompression spring 8|. Similar lugs depending v`from the bearing boxes 54-54'rorm seats for the upper ends of said compression springs. Adjusting screws 83- 83 threaded in cross pieces 8484, extending across thertops or the vertical guides 55-55,are adapted to engage the top' sides of the bearing boxes 54-54, and adjust the spacing of the scarring wheels 5|-5I with respect to the backing roll 56 against the springs 8I-8I to determine the depth of the groove formed by said scarring wheels. Lock nuts .85-85 threaded. on said vadjusting.screws are provided to lock said screws andfscarring wheelsv in the desired position three equal divisions, each of lwhich divisions may beequal to the length of the finished tubular pin. One scarring Wheel 5| abuts at its outer side, a collar 86 secured to said shaft as by a pin 81. The outer side or the other scarring wheel is abutted by a nut 88 threaded on a sleeve 89 Asuitably secured to said shaft. A spacing colf lar `9i! serves to space said'scarfing wheels the desired distance apart. The two scarring wheels are thus freely rotatable with said shaft 53 during the scarring operation and the space between the cutting .edges of said scarring wheels may be adjusted by substituting spacing collars 90 of various desired widths. Also, if desired, .one scarring wheel only can be used to divide the strip into two parts.-ormore than two scarring wheels may be used where it is desired to divide the strip into more than two or three parts.

' The outer edges of the strip are scarred to bevel opposite ends of the completed pins by means of scarring cutters 92-92 adjus'tably mounted in tool holders 93-93 (see Figures l and 4). Said tool holders are suitably `mounted on and extend inwardly of the inner sides of the side plates l5|5. Said cutters may be of-any well known form arranged to scarf the outer edges of the strip, so are not herein shown in detail. y 1 During the operation of forming the tubular pins, the strip steel isrinitially trained from a suitable reel or uncoiler (not shown) through the gibbed guide 51 through the space between the backing roll 56 and scarring wheel 5|-5|, through the gibbed guide 61 and between the advance pinch rolls vl1 and 20. During this initial operation of starting the strip through the ma-` chine -the scarring wheels 5l--5I are out of engagement with the strip. As soon as the strip, however, has been trained through the advance pinch rolls VI1 and 20, the scarring rolls-5|5l may be gradually engaged with the strip by tightening the adjusting screws 83-7-83 until said scarring wheels are close enough to the backing roll 56 to form V-shaped grooves of the desired depth inv the strip, which may be equal to at least one-fourth the thickness of the strip.V The -lock nuts 85-85 may then be tightened, to lock said scarng wheels in position. At the same timer the scarring cutters 92-92 may likewise be adjusted -to scarf the outer edges of the strip to the required bevelfwhich should conform to the bevel of the grooves cut by the scarring wheels 5I-5 l .c The motor 29 may then be started tovstart the pinch rollsl I1 and 29 in operation and groove and bevel the outer edges of thestrip. The strip is thentrained from the discharge pinch rolls l1 and 29 Abetween the.v feed rolls 48--48 ofA the shearing and feeding apparatus I 2,'through a longitudinal guide 94 formed there-v in and through. an aligned guide in a feed table 96 of said shearing' apparatus. Said shearing and feeding vapparatus is of a form shown in application Serial No. 49,399 iiled by Verne P. Donner, September 15, 1948, issued as Patent No. 2,546,390 onMarch 27, 1951, and entitled Cutting and Feeding Machine, so need only be described herein to the extent necessary to make myl vpresent invention readily understandable. The strip is trainedalong the guide 95 over a hardened steel insert 91 inthe end of said table 96. the edge of which insert forms a cutting edge cooperating with the cutter 50 (see Figures 6and7). v

Feeding of the stripalong the guides 94 and 95 im'ltfandlmllvbridge'zan endless rchinzlze l in th Y#ble '149242 andff1amerofthe mach: neat trieguids matelas-1i 'mgtra'sverselvv L"'ffm guide' a fp1i1'ral-if5ioies upwardly therefrom; above ltlreft'opfsuriaoelfo th rib lo' Iarid-ithe--guizie-p1ate 405; asf-showin ri Figure" l said guide fingers extendinglupwardly ito'lthe Spaeeiibetweentlfe guideiplateflfd tho-imputa engage tlilblankslflefto move t ein alefrgeaid mand-guide @latein aldireetiontrine 'vrsel-yof .theflengthsof ltheetriplandlot th grain 'striueture iif-.trie .blank formeel.

. Dliringiz'allefoperationfotxzutting the'flilariksl-IB from thladingfend ff-thestfidffeedmgxmeve; meiftxbf-zt-h'v str-ip' -wil-l'f-stop arid: Viea'riot':be:'ad'- vancedv until the cutter 50 is raised out off'rgthe patnfof the stripes ail-movies-rupwamiy inozposirollsIf'I arid 'S20-1 being continuously! driven-twill the spaeebetweeh' the discharge endoff'thgude )plateH151vv and rib" IM land thepn rolling-appa'- ra-I'AisV and-serves toffgu-idethe blanksl I3 '-toffthe nipsiibetween feeding -rolls `vv`I I'I-J-I II off-the'tub rolliiig' apparatus' I4.

The "tubular pin rolling apparatus elar'ly'y shown and described fin; the ]?tt=1"s?'t al.

*application SerialNo. -'41;633 *mentioned before,A f

= The first:roller-stemmiinciu'desithe:ceperatimgl enargeexmitefa ringer trzsriuffizme gidelzz feeealroirersm'IL-'ll n. 'rhezguidef annientare-fthe' be molled'f which :are .ffveryfmuclfshoiteithamthe distaneezbetw'eenfthe enteiingied'receivingnls of tli- Vguides:l entering; andileavingA themIasrbe#v tween each pairfcff rolls. .Whenrleavingts'aidirst manine; i. A :rib: Yor:lirfgert28? entersrffwel'lelnt the nip of the second set of forming/roll#25H16 atilthef. diseratirgle' end thereof andi'for sta" rib on ther' bottom tof gudelIfZB tol re'oeiv'e he par? tiarlly :formed: blanks' -andftoiguar 1th agfxt rotationiabnutatheinfaxes; :asfthey maratea-mfom# in'giifollsxY :125;1f-Ig2s aftauleveresughtiif iwerffthan mi 'mp animar-guia pqrt for the plank the slot intherfoi thegu frigeifandthjgiiidf iige its a @mitte-11:. As'V :thermaux-isi fumier-formed so tli. form-mtsanzfeldngfaztdflslot ye" :dat

it more closely resembles an arc of a circle, as f .whenpassing between the rolls |30v and I3I its ends have started to turn inwardly as indicated by reference character I Id in Figure .21, and the ends thereof engage shouldered portions |32 of the male roll |30, which hold it -from rotation about its axis as it enters and leaves said forming rolls; as shown in Figure 26. At thisfstage of the operation as shown in Fig- 'ure 11, 16 and 2l, the blank has startedto break -along the outer edges of the grooves Ila due to bending of the blank along said grooves during the successive rolling operations, as indicated yby reference character Hein Figure 21.

Ih'Figure 27 the blank is shown in a still further form of development between male and female rolls |33 and |34a and is beginning to come into the form of an arc of a circle. At this stage the inner lower edges of the blank engage opposite sides of the mandrel of the male rolly and is held from twisting or cookingl movement by engagement with the sides of the mandrel and thus is of itself held from twisting as it passes between said rolls and4 is ready to be broken along the Igrooves IIa- Ila into individual blanks having opposite beveled edges (see Figures 12, 17 and 22).

During the nextrolling operation the blank being formed between rolls |35a, I36a, Will break of its own accord into individual blanks of.

.lengths equal to the` lengths of the nished 'pins, due to fatigue of the metal-caused bythe 4bending of the blanks along the grooves ||aas the blanks are slightly elevated and bent along said grooves, as they pass between each set of .forming rolls.l From this point on, the short blanks, much shorter than the distance between -the entering and discharge ends of the respec- .tive guides, are capable of sustaining themselves during the rolling operation Without twisting,

entering the nip between` the4 forming rolls on .their respective guide and engaging the sides of vthe anvil of the associated male forming roll,

.fas -is shownin Figures 28 and 29.

During the final rolling stages, as shown in A Figures 30 to 33, inclusive, the blanks are engaged by ribs |34, |35, |36 and |31, projecting into the forming recesses of female forming rolls |39, |40, |4| and |42 respectively. which guide v-the blanks through the nips of the respective forming rolls and hold them from `rotation during the forming operation thereof and also cooperate with the respective forming Arolls to hold .the blanks to their required form. Where it is .desired that the pin have no cleft gap along its length, the supporting rib may be eliminated for the nal forming stages.

It may be seen from the foregoing that a suc- `cession of grooved blanksyor slugs I3, each comin end to end relation to the rst formingrolls;-

I I 9, |20 to produce U-shapes whichare guided to 'the subsequent forming rolls and further formed "into C-shapes before being separated into their individual segments.

lciently C-shaped so that the segments can be When the blanks are suiheldl against twisting upon further forming, the blanks are formed into tubular shape and as vrthey arethus formed they break apart at the grooves into their individual segments. The suc- 'cessive forming rollsy are. operated at progresf Y or bunching .up ofthe slugs atany stage.

`their length, they will break into their individual segments valong the groove by fatigue of` the metal caused solely by the forming action.- thereof,y and lthey will pass through thel remaining .forming operations,- severed into Vindividual blanks of lengths equal to the desired lengths of the nished pins having Vopposite beveledrends and much shorter thanpthe distance between the entering `and receiving endsof 'the guides lead-f ing to and from the nips between the `forming rolls. Y A 'v It may further lbe seen that a novel and sim,- plied process of forming short tubularpins, much shorter than could heretofore be: formed by rolling methods, has been provided Whichcon.-

sists in grooving strip stock in the direction ofy its grain into divisions determined by the d'esired length of the iinished pin, then continuously shearing the stock across its grain into blanks of lengths determined by the desired circum-.

ference of the finished pin and then passingnthe grooved blanks through'a series of rolling ,operations where theywill break into individual blanks of lengths equal to the length of the completed pins when suiiiciently formed to be self-sustain,-

ing yduring the balance of the rolling operations.

While I have herein shownand described .one form of apparatus Afor carrying out the-method of my invention, I wish it to be understood that various details of the operation and construction of the apparatus may be varied withoutdeparting from the principles of my invention, and thatfI do not propose 4or wish to be construedas ilimitingmyself to the specic method and apparatus shown'v excepting as expressely limited bythe appended claims.

I claim as my invent-ion: 7 f. fj 1. The method of forming short-tubular metal ,pins from continuous strip stock comprising the steps of feeding and longitudinally grooving the strip stock in accordance With'fthe desired length ofthe finished pins, shearingthe strpftransversely of the length thereof into blanks4 cipredetermined length; determined of the desiredV circumference of the finished'V pins, feeding,-A the grooved 'blanks at right-angles.A to lthe direction of the grooves formed therein, "thenpasvsing the grooved blanks through successive rforming stages and breaking the blanks into individualjzblanks vof the length of the finished pins solely; bythe forming action thereon, subsequent torthe'initial forming stages and prior yto the iinal forming '3i-The method ofV formingl short:tubularfmet Y alzi pins- .fromi'f continuous strip stock comprising groovingfthe"stock` len;=,fthvvise` into equal divisions "determined-by: the rdesiredf lleng'th'of the finished pinsgftl'ren shearingl-thegrooved strip transversely offthe lengtlrthereof-finto blanksofrlengthsfde- A,

"terminedg -by- .the L required circumference oif the iinishedi pins," feeding the f grooved' blanks V4with the@ gro'ovedl fportionsfthereof; extending trans- :versely tothe. direction of traveler the yblanks during:Y the: feeding operation thereof; f then guidi ingiandrpassingthevgrooved blanks through a' series fofl lsuccessive lrolling r and f forming stages andbreaking :the `l`blanks; into individual blanks of lengths equal to the length'of the finished pins along'the` grooves formedlthereim subsequent vtoil-the..initial forming :stages land-fprior toA the 4lnal'forming. stages, -solely'ofy the for-ming action thereon.

idIhefmethodfofcforming. short tubular metal. f pins from` continuous strip stock rcomprising grooving' thei'stripl in the. direction of. its grain intovequal divisions :determined by theV fdesired l'length-f" of the :finishedpins to: depths. equal to 'atleaSt-one-.ourth vthe thickness ofthe strip then shearingthe grooved. :strip.-transversely. offfthe g'rain' thereofinto': slugs of `equalflengtl'is deteri'nijnedlby the desired' circumference ofthe iinishedapins; feeding the grooved'slugs transversely offthe graingthere'of and-i passing the grooved slugs Athrought'successive rolling and forming stages, and` `breaking the partially:form'ecl slugs into rndividual I blanks along thegroovesiormedf therein vsolely byzthezforming action: thereon; :subsequent Y to` .theiinitialv .forming stages and prior-1 to 1the .final forming stages.l

175. In a. method of rollingishort.:tubularrmetal pins from continuous strip :stock bya succession fof spacedlforming oper-ations .whereirrthe` finished ity 'of f spaced successive forming operations, and

'breaking'fthc 'blanks Y-into individual partially l-formfedblanks `along Vthe lines offthe grooves AformedY l thereon-k solely--by J the -forming .faction 'thereomsubsequent tol the initial forming opera, ition=and-priorato the final forming operation.

L1' fTheimethodlof- .fcrmingshort tubular metal pins from continuous strip stock comprismgthe steps 'oflieedin'gfanggrooving2 thestrip stock in 'thedire'ctionof its-grain and in accordance with '.the'desired length` of' the finished pins, shearing `the strip-.transversely oiithefgrain' thereof into blanks "ofppredetermined length, determined by thezvdesiredcircumferencecf the finished pins, 'afeedinga'the grcovedblanks transverselyof the *grain v,thereof :andi passing fthe; :gmovedablanks through aplurality of successive leuning stages,

fcgrssagoies 'endif-.then y= breakingifthe .blanks intofzindividual 'pieces' solelyby the forming 'actionzthereonfafter saldi blanks have4 vpassed through: suliieient forming-stages to be 'self-sustainingzthroughitheibal ance of' the forming stages; "l 7;:In afmethodzof Aforming'short tubular metal pins from .continuous istrip stock' by; shearing-the 'st'rizvstock into blanks. ofspredetermined length and subiectingrxthe blanks. successively. tofanpl-urality of forming operationsewhichzsareseparated at .greater'distances than the lengths :ofthe blanks, Ythefimprovenuent comprising'sgroovingfthe strip" into ,equal divisions along: the l directionof its grain: prior .'tofthe shearing operatio'ng'fthe Width of said fdivisions .being determined byLthe :requiredrlength iof thennis'hedpin, the-'grcove 'being'.vshaped anditsgdepthbeing at .leastiequal to onef-ifourtlithe.thicknessrof;theastripztcfhold the .grooved blagnksiwhen shearedr. frorrr'the; strip stock' in connectedf relatonaduring the; :initial forming operations t and to permit :said .fgreoved blanks tot break into(I individual. lblanks, foil-the lengths of the1nished pins, .when sufficiently fformedztorbe individually: self-:sustaining they arel subjected .ton the iinalforrning operations.'

i 8. lnaamethod:oiormingsshort tubulanmetal pins from continuous strip. stock by shearing :the strip stock into' blanksi off :predetermined: i length and subjecting` the `blanks `to a successionfof spaced Vforming operations which :are separated by "distances greater. vthan' the lengths 'i ofi the blanks, the improvement comprising -fgroovng stripL stock along' the directionof'sits grain: -to 1a .suiicient Y depthl'that' cause breakage #when 'the' stocke' is bent into tubular form,l -shearing'the stock transverselyto form-'groevedAblanksgisuccessivelyfdeforming-'the blanks into tubular-shape, and Eallowing the blanks' to'ibreakfat. the" grooves `thereof intoY separate pins only riafterftlfie blanks areappreciably deformed.

92"-Il'1emethod of making tubular members ircmf metal `strip stock which comprises longit'udiniallyl grooving thest'rpvv stock, cutting lillle grooved strip stockffacrossvthev Widthithereo 'to lformian individual blankV composed along its gated guide surfaces,- and;breaking: the. blankv along the grooveintoindividual'ftubular segments. 102 'The method-of Amaking tubular members frornmetal strip stock which comprises beveling the sides of metal strip; stock to formoppositely inclined edgesfcuttlng a longitudinal -V-groove in the strip stock betweenfthe sidesi'cf the stripwith feach side of the lv'eglonveinclined oppositely `t0 'the nextadj'acent inclined edgeiof the strip, cut- .ting the beveled and grocved strip acrosstthe Width thereof` to Aforman .individual blank., composed alcngits length ofrgroove separatedrbut interconnected segments, 'successively` Ybending fthe blank; along `:its lengthin at pluralityrof 'spaced .operations to'- prozduce a tubular shape'with the `inclined. .edges 'and :groove sides .around-.the outer surface of the tubular .shapeguiding the. blank with the segments' in" connected relation during zthe. linitial bending steps Pto .provide :elongated guide surfaces;I and .breaking :the blank cat. the

groeve to form individual `segments with beveled ends: during.' `the i flnalgbending; operations after thelbiank. has leeeni` suiiicientiy .bent to prov-ide f 13 each segment with guide surfaces thatwill prevent twisting of the segments during the subsequent bending operation.

ARTHUR FRANK ZITZEWITZ.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 351,987 Lewis Nov. 2, 1886 515,270 Zimmerman Feb. 20, 1894 642,901 Glader Feb. 6, 1900 653,900 Bray July 17, 1900 653,911 Heggie July 17, 1900 653,913 Heggie July 17, 1900 935,906 Grant Oct. 5, 1909 1,040,398 Parmelee Oct. 8, 1912 Number 14 Name Date Muller Nov. 23, 1920 Berg May y24, 1921 Howarth Feb. 14, 1922 Kirsch Feb. 23, 1926 Bundy Sept, 7, 1926 Podee Oct. 12, 1926 Klocke Dec. 30, 1930 Birckmayer Dec. 8, 1931 Poepellmeier Aug. 1, 1933 Davis Aug. 29, 1933 Klocke June 26, 1934 Davis June 25, 1935 Sussman Dec. 17, 1935 Iversen June 9, 1936 Keller Sept. 7, 1937 Riemenschneider Aug. 23, 1938 Humphrey Nov. 26, 1940 Nordquist July 6, 1948 

